MacroKit is a free, browser-based media toolkit that splits, converts, crops, and merges video, audio, and image files entirely on-device with zero uploads.
What is MacroKit?
MacroKit is a suite of local-first media tools that run in your browser using WebAssembly (ffmpeg-wasm). It accepts common formats like MP4, MOV, WEBM, MKV for video; MP3, WAV, OGG, M4A for audio; and PNG, JPG, WEBP, AVIF for images. Outputs include converted, split, merged, or extracted media saved directly to your disk. No account, no upload, no file-size limit. The tools are hosted at macrokit.app with no company or creator name listed on the page.
Key Features
- Zero-upload processing — Files are read into local memory and never leave your device; no server ever receives the data.
- Video Splitter — Cut MP4, MOV, WEBM, or MKV clips into exact, frame-accurate segments without re-encoding the whole file.
- Video Merger — Stitch multiple MP4, MOV, or WEBM clips into one seamless output file.
- Video Converter & Compressor — Switch formats and codecs with quality control (CRF presets) and reduce file size using H.264 compression.
- Audio Extractor — Pull a clean audio track from any video file and export as MP3, WAV, AAC, or FLAC.
- Audio Splitter — Slice MP3, WAV, OGG, or M4A recordings into chapters or individual tracks.
- Image Cropper & Converter — Crop to exact ratios or pixel dimensions and batch-convert between PNG, JPG, WEBP, AVIF.
- PDF Toolkit — Merge, split, and reorder PDF pages locally, with support for PNG and JPG input.
- Offline capability — Once a tool has loaded, you can disconnect from the internet and continue processing.
- No watermarks, no accounts, no file-size limits — all tools listed on the page are free.
Who is it for?
- Privacy-conscious users — Anyone who wants to process sensitive video, audio, or images without sending data to a cloud server.
- Video editors and content creators — People who need to quickly split a long recording, merge clips, or extract audio for podcasts or social media without installing desktop software.
- Users with large files — Those working with 4K video or long audio recordings that exceed typical upload limits (e.g., 2 GB+) can process directly in memory.
- Casual media converters — Anyone who needs to convert a video format, crop a screenshot, or reorder PDF pages without signing up or paying.
What can you do with MacroKit?
- Split a long recording into chapters — Use the Audio Splitter to cut a podcast MP3 into track markers, then export each segment as a separate WAV file.
- Convert a video for social media — Use the Video Converter to transcode a 4K MOV to a compressed MP4 with a specific CRF quality preset.
- Crop and resize screenshots for the web — Use the Image Cropper to trim a PNG to exact pixel dimensions and convert it to WEBP for faster page loads.
- Extract dialogue from a video — Use the Audio Extractor to pull the audio track from an MP4 and save it as an AAC file for transcription.
How does it work?
The workflow runs entirely in your browser: drop a file into the tool’s window, which reads it into local memory. The file is then decoded (demuxed), processed using ffmpeg-wasm, encoded (muxed), and finally saved to your disk. No upload bar or render queue — work begins immediately and finishes at your machine’s speed.
FAQ
Are my files uploaded?
No. Every tool runs in your browser via WebAssembly. Your files are read into local memory and processed on your device — they never leave it, not even to MacroKit’s servers.
Is it free?
Yes. The tools are free with no account, no watermarks, and no file-size limits. No paid tier is mentioned on the page.
How large a file can I process?
There’s no upload, so the only limit is your device’s available memory. Large files process as fast as your hardware allows. The page states “no limit on file size.”
